Regenerative heat exchanging apparatus



April 17, 1951 c. E. H. ECKERSLEY REGENERATIVE HEAT EXCHANGING ARPARATUS Filed' July 21, 1947 5 Sheets-Sheet l ATTORNEY April 17, 1951 c. E. H. ECKERSLEY REGENERATIVE HEAT EXCHANGING APPARATUS 5 Sheets-Sheet 2 Filed July 21, 1947 A v w INVENTOR. C/lar/es fi. Edens/er ATTORNEY April 17, 1951 c. E. H. ECKERSLEY REGENERATIVE HEAT EXCHANGING APPARATUS 5 Sheets-Sheet 3 Filed Jul}, 21, 1947 m f w w A IJ? w 4 h 5. o w o o 0 f w N\ llllllllllll c. E. H. ECKERSLEY 2,549,583

REGENERATIVE HEAT EXCHANGING APPARATUS April 17, 1951 5 Sheets-Sheet 4 Filed July 21, 1947 llll.

IN V EN TOR. (bar/a5 /7. (fans/) A TTORNH Ap 1951 c. E. H. ECKERSLEY 2,549,583

REGENERATIVE HEAT EXCHANGING APPARATUS Filed July 21, 1947 5 Sheets-Sheet 5 Q INVENTOR.

fidr/e's flfbfers/cg/ BY ATTORNEY Patented Apr. 17, 1951 UNITED REGENERATIVE HEAT EXCHANGING APPARATUS Charles Ernest Holland Eckersley,

Newlands,

Glasgow, Scotland, assignor to The Air Preheater Corporation, New York, N. Y.

Application July 21, 1947, Serial No. 762,522 In Great Britain May 8, 1944 Section 1, Public Law 690, August 8, 1946 Patent expires May 8, 1964 4 Claims.

The invention relates to regenerative heat ex'- changing apparatus, herein, for brevity, referred to as air preheaters of the type in which the heat transmitting material is packed into compartments formed by radial and circumferential division plates of a cylindrical rotor which rotates inside a stationary casing connected to ducts conveying the working fluids to and from the apparatus. 7

One of the drawbacks experienced in the operation of modern boiler plant is the fouling of heating surfaces by ash deposits which with the use of certain kinds of coal and under certain firing conditions can become so solidified and adherent that the usual method of soot-blowing by steam jets will not dislodge them. Such deposits can be cleared away by washing by means of high pressure water jets preceded by soaking in an alkali solution.

Hitherto it has been necessary to withdraw the heat transmitting material from the preheater for treatment with solution or to fit temporary splash boards and troughs inside the ducts for catching and draining away the Water used. In either case not only the preheater but usually the whole plant of which it forms part had to be put out of commission.

According to the present invention I provide in each of the ends of the casing a door which is large enough to give ready and direct access from outside to the sectoral compartments of the rotor and to allow the heat transmitting material to be washed while it remains in its place in the respective compartment of the rotor and without any need for an attendant to enter the ducts.

The heat transferring material is assembled into packages arranged for ready application of lifting tackle, and the size, shape and outline of the access doors are such that withdrawal or replacement of the packages is possible without interference with any other parts of the rotor, while the boiler or any other plant of which the preheater may be part is kept in operation and the working gases continue to pass through the preheater.

For convenience I shall first describeone embodiment of the invention as applied to a preheater with the rotor revoluble about a vertical axis, as it may be used to transfer heat from the flue gases to the combustion air of a boiler reference being made to the accompanying drawings in which;

Fig. 1 is a side elevation, partly sectional on theline l-l of Fig. 2 of an air preheater of the type referred to, showing package removal and washing arrangements according to one embodiment of the invention, the ducts by which fluid is led to and from the rotor being omitted;

Figure 2 is an end elevation also partly sectional, the plane of the section being through the line 22 of Fig. 1;

Figure 3 is a plan view;

Figure 4 is a plan view drawn to a larger scale, of one sector of the rotor shown in the preceding figures;

Figure 5 is a fragmentary plan view drawn to a larger scale showing in detail the construction of the plates of the sector shown in Figure 4;

Figure 6 is a plan, drawn to a larger scale of one sector of the rotor with a heating element package in position therein, according to one arrangement of the invention;

Figure '7 is a fragmentary sectional View through the line 1-'l of Figure 6; i

Figure 8 is a fragmentary sectional view drawn to a larger scale through the line 8-8 of Figure 6, showing spacer elements and upper and lower seals;

Figure 9 is a fragmentary sectional view showing a support for a package;

Figure 10 is a fragmentary plan drawn to a larger scale of the top door and adjoining parts of the apparatus;

Figure 11 is a fragmentary sectional view through the line H-ll of Figure 10;

Figure 12 is a similar sectional view at right; angles to Figure 11 through the line |2|2 of- Figure 10;

Figure 13 is a plan of a rotor sector accordin i to another form of theinvention, the heat transferring elements being omitted for clearness;

Figure 14 is a fragmentary section showing radial seals, sector plate opening and partially withdrawn package;

Figure 15 is a plan of another form of sector,

also with the heat transferring elements omitted; Figure 16 is a fragmentary section through the line Iii-46 of Figure 15;

Figure 1'7 is a like section through the line I1I! of Figure 15; and Figures 18 and 19 are a front elevational and distinguished where necessary by the addition-of an exponent.

Referring to the drawings the rotor I .with its sectors 2 formed by radial division plates 3 and sub-divided into compartments by circumferential plates 4 is suspended by a thrust and journal bearing 5 mounted in the center of an upper girder frame *6 and steadied at the bottom by a journal bearing 1 carried by a lower girder frame 8.

In the two end walls [0 of the casing openings for air and gases are cut on opposite sides of the girders to connect with the ducts 21, 28 (Fig. 2). form part of the girders and in cooperation with flexible metal strips ll fixed to the .radial division plates 3 of the rotor I provide a seal preventing leakage of air along the end walls to the gas space of the preheater, see Figures 8, 11 and 12.

Within the confines of each girder an opening l'2, Figure 10, is cut through the respective end wall Ill to give direct access from the exterior of the casing to the rotor compartments. The openings l2 correspond substantially in Size and outline to the horizontal section through one of the rotor sectors. They are arranged symmetrically to the same radial plane through the rotor axis and are closed by upper and lower hinged covers l3, l3 whose interior faces are flush with the inside of the casing end walls. The covers are kept gas tight by means of clamping devices 14, see Figs. 10, 11 and 12.

Liners built up from corrugated and fiat plates 15, i6 are fixed by means of clamps I! on the sides of the radial division plates 3 of the rotor. The thickness of these liners is such that they reduce the circumferential width of the rotor compartments to slightly less than that of the free space between the radial seals of the rotor.

Referring to Figures 4 and 5, the heat transferring material consists of corrugated metal sheets l8, H! which are bundled into shells 50 and form packages which fit closely into the several rotor compartments.

A flat plate is built into each package. The upper and lower ends of the plate 20 project .beyond the body of the package. The sheets l8, I9 are supported on bars 2| which bridge the spaces between the plate 20 and the respective shell 50. Bars 2| which bridge the top of each package are provided with holes where suitable for lifting tackle. The shell 50, plate 20 and bars 2|, 2! together form a convenient carrier by means of which the respective package may be lowered into, or lifted out of, the respective rotor compartment in a straight vertical drop or lift without touching the radial seals. The ends of the supporting bars 2| rest on bearers 22 attached to the package shells.

In the construction illustrated in Figures 6,, 7.,

8 and '9, the projecting upper ends of the plates 20 are also furnished with supporting bars 2|, see Figures 6 to 8. 23 denotes a guide which may be temporarily inserted when the packages are being inserted or removed. In the construction shown in Figures .13 and 14 in which parts corresponding to those previously described are indicated by the same reference characters distinguished by the addition of the exponent a corrugated spacer elements I 5a are welded to the radial division plates 3a. Each package a, b, 0 includes built-in plates and supporting bars. The inward end of the sector is blanked off at d, see Fig. 13.

In another alternative arrangement as illus trated in Figures 15, '16 and l7,'in which parts corresponding to those previously described are indicated by the same reference characters distmgurshed by the addition of the exponent b The remaining portions of the end walls the radial seals l lb are so made that they do not at any point project beyond the forward side of the radial division walls 31) of the rotor. No liners :are fixed to the latter, but the packages of the several compartments are each split into two pairs A, B and C, D, preferably of equal size, each package being built around its own carrier. The packages when in position are separated by a fiat division plate 231) fixed to the carrier of one of them by means of lugs 24 and bolts. When inserting these packages into the rotor the forward package of a pair is first lowered until its top edge is below and clear of the edge of the respective seal and is then moved or swung in below the seal and put down on its bearers. The second or rear package of the pair can then be lowered into its place without touching the radial seal. In the reverse operation of removing the packages from the rotor the rear package is taken out first in a straight vertical lift. The second package is then raised until free of its bearer, moved sidewise until clear of the seal, and then drawn in a straight lift.

The withdrawal of packages A or C gives ample room for the withdrawal of packages B or D.

As the width of the access doors exceeds that of the open space left between the radial seals. the packages of any of the described arrangements when lifted vertically from their compartments in the manner described, will pass freely through the door openings. The packages can therefore be taken out of, or put into, the preheater through the upper doorway, with the radial seals left in position, and without need for the attendant to enter any of the ducts leading to and from the preheater. The rotor is stopped for this purpose so that one of its sectoral compartments is just below the access door I3. In this position the radial seals prevent troublesome escape of air or gas so that the operation can be performed while the plant of which the preheater forms a part is working and while .gas and air continue to pass through the preheater.

To provide for washing the packages of heat transmitting material while they are in their rotor compartments, a gallery 26 (Figs. 1 and 2) is built at a convenient level across the space between the ducts 27, 28 leading up to the preheater to give access to the lower access door I3. The gallery has a floor 29 of grating or perforated metal beneath or opposite of the lower access door i3. Below it there is a trough 30 with drain 3| and splash boards 32 (Fig. 1) extending from the floor up to the preheater casing. A winch 33 is provided for operating the lower door through the medium of a rope 33.

To wash the heater, the two access doors l3, l3 to the rotor are opened and the rotor is stopped with one of its sectors fully exposed at the doors. An alkaline solution is first applied in a slow continuous flow at the top of the rotor. A high pressure jet of water is then used to remove the softened deposit. The solution and water are drained away through the grating 29 of the gallery '26, provision being made for recirculating the solution.

If desired, separate air and gas by-pass ducts may be provided as indicated in dot-and-dash lines at 2?, 28 respectively, in Figure 2.

The adaption of the invention to a preheater with a horizontal axis is illustrated in Figures 18 and 19 in which parts corresponding to those before described are indicated by the same reference characters with the addition of the exponent c. The rotor shaft 3;! is conveniently carried by journal bearings '34. 35 denotes columns carrying the bearings 34, gearing 3%, Bl and the motor 37 driving the rotor. The hinged doors at I30 giving access to the rotor are vertically below the bearings. These doors aresimilar in construction to the doors i 3 described and illus trated in Figure 10. The package of heat transferring material may comprise one per compartment, with the radial division walls provided with liners, or they may be in pairs in unlined compartments. The packages are preferably each built up'between two heavy plates 38 which are at both ends linked through welded-on lugs 39and pins to strong connecting bars iil. v The packages must naturally be inserted and withdrawn horizontally and the bars are provided with holes suitable for application of Withdrawing and lifting gear.

For washing purposes a trough or hopper 4! with drain A 2 is arranged below the doors, forming an integral part of the preheater casing.

What I claim is:

1. In a regenerative heat'exchange apparatus having passages for a heating gas and air or other gaseous fluid to be heated, ducts for supp-lying hot gas and relatively cool air thereto, and a cylindrical rotor interiorly divided by radially extending partitions into sector shaped compartments carrying regenerative material adapted to be moved first through the gas passage and then.

into the air passage; a housing extending around said rotor; sector plates closing the ends of said housing and formed with a pair of circumferentially spaced openings communicating with said ducts for enabling the flow of gas and air through said rotor with another aperture located intermediate said openings having a circumferential extent corresponding substantially to the width of a sector shaped compartment; and access doors for said apertures hinged to said sector plates at opposite ends of the rotor to permit access to said regenerative material in a rotor compartment while the gas and air flow through other rotor compartments and without any need for entering either said gas or air duct.

2. In a regenerative heat exchange apparatus having passages for a heating gas and air or other gaseous fluid to be heated, ducts for supplying hot gas and relatively cool air thereto, and a cylindrical rotor interiorly divided by radially extending partitions into sector shaped compartments carrying regenerative material adapted to be moved first through the gas passage and then into the air passage; a housing extending around said rotor; sector plates closing the ends of said housing and formed with a pair of circumferentially spaced openings communicating with said ducts for enabling the flow of gas and air through said rotor with another aperture located intermediate said openings having a circumferential extent corresponding substantially to the width of a sector shaped compartment; and access doors for said apertures hinged to said sector plates at opposite ends of the rotor to permit access to the rotor for cleaning said regenerative material in a rotor compartment while the gas and air flow through other rotor compartments and the material remains in its place in the compartment and Without any need for entering either said gas or air duct.

3. Regenerative heat exchange apparatus as recited-in claim 1 in which the rotor is suspended by a bearing mounted in an upper girder and steadied at the bottom by a bearing carried by a lower girder, openings being provided in the respective end walls of the casing between splayed ends of the girders corresponding in size and outline to the horizontal section through one of the rotor sectors, and covers clamped over said openings,

4. In regenerative heat exchanging apparatus as claimed in claim 1, packages of heat transmitting material each comprising corrugated metal sheets bundled together and having flat plates built into each bundle and adjustably joined by supporting bars together forming a carrier for the package.

CHARLES ERNEST HOLLAND ECKERSLEY.

REFERENCES CITED The following references are of record in the file of this patent: 1

UNITED STATES PATENTS Number Name Date 1,970,534 Colby et al. Aug. 14, 1934 2,224,787 Horney Dec. 10, 1940 2,432,198 Karlsson et al. Dec. 9, 194.7

FOREIGN PATENTS Number Country Date 503,857 Great Britain Apr. 17, 1939, 

